Vacuum collection systems have been used in a wide variety of applications to collect and transport waste water. For example, vacuum collection systems are used to collect sewage from bathrooms on airplanes, trains, and ships. The systems are also used in non-sewage applications to collect used or dirty process water, also known as gray water.
Vacuum collection systems are used in place of conventional gravity drainage piping to facilitate installation and pipe layout changes. In a conventional drainage piping system, pipe inlets are located below waste water sources and feed into drainage pipes leading to a sewer line. The piping in such systems must be continuously sloped so that the waste water flows away from the source and into the sewer line under the force of gravity. As a result, pipes for gravity drainage systems are often laid in or underneath a concrete pad supporting the facility. This pipe location not only requires significant amounts of additional plumbing work, but also complicates changes in facility layout, in that portions of the concrete pad must be ripped up to expose the piping.
The vacuum collection systems, however, use suction to collect the waste water, thereby, eliminating the need for downwardly sloped pipes. The vacuum collection systems typically comprise a collection drain located under each waste water source and one or more collection branches leading to a main vacuum pipe. The main vacuum pipe is connected to a pump which creates negative pressure in the main vacuum pipe and branch to thereby pull liquid through the branch and main vacuum pipe and into an attached collection tank.
Significantly, vacuum collection systems allow the use overhead drainage piping since suction, rather than gravity, is used to transport the waste water. The piping in vacuum collection systems does not need to be laid in concrete below the waste water source, but instead may follow overhead electrical and refrigeration service lines. Thus, plumbing layouts are simplified, and waste water generating equipment may be quickly and easily relocated within a facility without ripping up concrete.
While the use of a vacuum collection systems allows greater freedom in routing drainage piping, the entire system may be rendered inoperable due to a loss of vacuum in a single branch. For example, a crack may develop in a collection line connected to the branch or a control valve associated with a collection line may be remain open due to a faulty activator. In either case, the entire systems is susceptible to a loss in vacuum which prevents the system from collecting waste water. Consequently, additional waste water may back up and spill onto the floor of the facility in which the vacuum collection system is installed.
Furthermore, locating the breach in the system is overly difficult and time consuming. Up to now, the easiest and most common method for detecting a breach in a vacuum collection system is to listen for air flow through the breach. The vacuum in a faulty branch, however, is very low, making audible detection of a leak exceedingly difficult. As a result, leak detection often requires each branch in the system to be manually isolated to determine the location of the leak.